Controller.



M. S. TOWSON.

CONTROLLER.

APPLIOATION nun MAY 19,1909.

8 SHEETS-SHEET 1.

Patented July 11, 1911.

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M. S. TOWSON.

. CONTROLLER.

' APPLICATION rum) MAY 19,1909.

Patented July 11, 1911.

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M. S. TOWSON.

CONTROLLER.

APPLICATION FILED KAY 19,1909.

Patented July 11, 1911.

3 SHEETS-SHEET 3.

Lin eu'o'e J MORRIS S. TOWSON, OF CLEVELAND, OHIO.

Specification of Letters Patent.

Application filed May 19, 1909.

CONTROLLER.

Patented uly 11, 1911. Serial No. 496,900.

To all whom it may concern:

Be it known that I, IVIORRIS S. TOWSON, a citizen of the United States,residing at Cleveland, in the county of Ouyahoga and State of Ohio, haveinvented a certain new and useful Improvement in Controllers, of whichthe following is a full, clear, and exact description.

The present invention is directed to a system for controlling electricmotors.

The object of the invention has been to provide a system wherein thetorque is con tinuous and not interrupted in passing from one speed toanother. The advantage of such a system in practical operation as, forexample, in connection with road vehicles driven by batteries, will beobvious upon an exposition of its character.

It will be seen that the above object is at tained by that embodiment ofmy invention described in the following specification and illustrated inthe accompanying drawings, in which:

Figure 1 is a diagrammatic representation of the connections between thebatteries and the motor through the controller. Fig. 2 is a developmentof the particular controller drum illustrated in Fig. 1. Figs. 3, 4:, 5,6 and 7 are diagrammatic representations showing the changes made in theconnections in passing through the various speeds. Fig. 8 is aconventional representation of the motor. Fig. 9 is a diagrammaticrepresentation of the motor and controller with the va rious connectionsbetween the two.

The system which I have here illustrated is that used with a motor ofwhich the field coils are series wound and sectional in their character.By sectional I mean that each pole is provided with a plurality of independent coils, and in the present illustration of the system I haveshown two coils A, A upon each pole. The relative proportion between thetwo coils is not material for the purpose of attaining continuoustorque, although I would suggest, as an effective arrangement forsecuring variations of speed in light vehicles, that one of the coilshave two to three times as many turns as the other. The larger coils A Iwill hereafter call the main field coils and the smaller A will becalled the auxiliary coils, but it will be understood, of course, thatthis nomenclature is employed for convenience of understanding only.

The system is shown as including the usual batteries and resistance R.The particular construction of the armature B or the controller Cemployed is immaterial, it being merely necessary that they shall be mechanically suitable. I have shown a controller of the drum type, but anyother type will do as well.

Referring to Figs. 3 to 7 inclusive, it will be seen that the systemcontemplates the establishing of connections at the first speed suchthat the current will flow through a resistance and through bothsections of all of the field coils, thus giving the strongest field andthe lowest possible speed to the armature. The next movement of thecontroller is, as shown in Fig. 4, designed to short circuit theresistance but to leave all of the field coils in series connection asbefore, thus giving the next higher speed. The next movement of thecontroller, see Fig. 5, is designed to break the connection through themain field coils and then establish them in series parallel, theauxiliary coils remaining without any change in their connections, therebeing shown in the present case two main coils in each series since thediagram refers to a four-pole machine. At

this speed the resistance will remain out as before and the strength ofthe fields will be diminished by reason of the fact that the currentwill now be divided in passing through the main field coils, althoughthe full current will continue through the auxiliary coils as before.From this arrangement a still higher speed will result. At the nextmovement of the controller, see Fig. 6, two of the auxiliary coils areshort circuited, the other coils remaining in the field as before. Atthe final movement of the controller, see Fig. 7, the rest of theauxiliary coils are short circuited, the current flowing only throughthe parallel series of the main field coils, thus giving the highestspeed of the systei It will be noted that many variations in speed areobtained and that although a slight spark is had in making the necessaryconnections between the second, and third speed, nevertheless there willbe a continuous flow of current through the field and the motorthroughout the entire range of possible change, and that I am thusenabled to obtain a continuous torque and a smooth and even action ofthe motor. It will further be noted that in attaining the higher speedsthere is no waste of current such as occurs in those systems where thefield is weakened by shunting part of the current and permitting thatpart to effect no work other than the heating of the resistant materialthrough which it passes.

In Fig. 1 a number of motor wires, designated 1 to 9, are shownextending from the controller C; and in Fig. 8 continuations of thesesame wires are shown properly connected to the different groups of mainand auxiliary field coil sections and to the commutator brushes,-themotor wires in Fig. 8 being arranged in the order and being designatedthe same as in Fig. 1.

In Fig. 9, wherein I have shown diagrammatically the motor, controllerand batteries, the different parts of the motor and controller areconnected by the motor wires shown in Figs. 1 and 8, and the fiverunning positions of the controller are shown by dot and dash lines,numbered 1 to 5. It will be seen that when the controller is in thefirst running position the contact fingers to which motor wires 2 and 3are connected, are bridged by reason of their engagement with a contactor segment of the controller drum, and that the arrangement andconnections shown in Fig. 3 will be obtained, the battery currentpassing in series through the four main field coil sections A, throughthe re sistance It, through the four auxiliary field coil sections A andthrough the armature B. It will be seen also from this figure that whenthe controller is in the second, third, fourth and fifth runningpositions the arrangements and connections shown in Figs. I, 5, 6 and 7,respectively, will be obtained.

Having thus described my invention, I claim:

1. In combination in a motor control system, a motor having a pluralityof sets of field coil sections, and a controller having means forchanging the relation of the sections of one set with respect to oneanother, without changing the relation of the sec tions of the otherset.

2. In a motor control system, in con'ibination, a motor having a fieldwinding comprising two sets of independent coil sections, and acontroller having means for connecting all the coils of the differentsets in series, and for changing the sections of one set from series toseries parallel relation without changing the relation of the sectionsof the other set.

3. In av motor control system, a motor having two sets of field coilsections, and a controller having means for varying the relation of thesections of one set with respect to one another, and for varying thenumber of effective sections of the other set.

4. In a motor control system, a motor having a field winding comprisingtwo sets of coil sections, and a. controller having means for varyingthe relation of the sections of one set with respect to one another, andfor short circuiting different numbers of the sections of the other set.

5. In a motor control system, a motor having a field winding consistingof two sets of independent coil sections, and a controller having meansfor connecting all the sections of two sets in series relation, forchanging the sections of one set from series to series parallelrelation, and for short cireuiting different numbers of the sections ofthe other set.

In testimony whereof, I hereunto a'lfix my signature in the presence oftwo witnesses.

MORRIS S. TOWSON.

lVitnesses J. M. \Voonwann, H. R. SULLIVAN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

' Washington, D. C.

